Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

i dont know what A records do.

and are they necessary for a web server to host multiple domains and how are they related to DNS?

share|improve this question
+1 because I'm not a fan of "browse-by vote-downs." Most likely they voted you down because you can look at a variety of direct answers to this with a simple Google search. - The Question if they are necessary for multiple domains is however relevant and fairly original. – Joshua Enfield Sep 28 '10 at 14:52
up vote 11 down vote accepted

An A record is a DNS record.

Specifically it's the DNS record that maps from a hostname to an IP address. Every URL that contains a domain name must go via an A record to find the IP address of the server that's hosting it.

See RFC 1034 and RFC 1035.

share|improve this answer

This is a bit of a loaded question, but I'll try to give a brief conceptual description. An A record is a translation of a Domain name to an IP address. When a computer queries out to find a domain (,, etc), it doesn't find it by the domain, but the IP; the DNS server gives the IP that it has in the A record when it receives the query for the domain and the computer then navigates to that address. It is of course a lot more complicated than that, but that is a high level description of what service an A record performs.

share|improve this answer

a quick example IN A 123.456.789.012 ;this is the public ip

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.